{"id":"CVE-2026-97952","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nsunvdc: unmap LDC cookies when the descriptor send fails\n\n__send_request() maps the request's pages into the LDC channel's map\ntable (ldc_map_sg()), fills in the descri…","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nsunvdc: unmap LDC cookies when the descriptor send fails\n\n__send_request() maps the request's pages into the LDC channel's map\ntable (ldc_map_sg()), fills in the descri…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= a11f6ca9aef989b56cd31ff4ee2af4fb31a172ec < ab81a5c1014a38dab0fb402609fd866b0bcb4726","Linux >= a11f6ca9aef989b56cd31ff4ee2af4fb31a172ec < 57835952566f0be9b365a6eb3a70b397a9d5ef47","Linux >= a11f6ca9aef989b56cd31ff4ee2af4fb31a172ec < f3322baa3a8ac87730feae952c1146269d78e098","Linux >= a11f6ca9aef989b56cd31ff4ee2af4fb31a172ec < 0c6da21fa35e03fc74f09895433ccd6d4a9c3530","Linux 627e656239c63d8a81672d08de7885e89c12fa75","Linux a1ef7d5da9b2c145f811a80bb8197df6037a7572","Linux 7ab4b6526fdcdfa7772984bbcd2ac4fd14fa223b","Linux 3fbba4e55051d01a72b56ea192064175924bf56a","Linux 3e380fc2ae4d18210eec9c472b12e2b2544f7dc1","Linux >= 4.4.175 < 4.5","Linux >= 4.9.156 < 4.10","Linux >= 4.14.99 < 4.15","Linux >= 4.19.21 < 4.20","Linux >= 4.20.8 < 4.21","Linux 5.0"],"published":"2026-09-25","updated":"2026-09-25","sourceUpdated":"2026-09-25T11:17:22.790","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-97952","references":[{"url":"https://git.kernel.org/stable/c/0c6da21fa35e03fc74f09895433ccd6d4a9c3530","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/57835952566f0be9b365a6eb3a70b397a9d5ef47","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/ab81a5c1014a38dab0fb402609fd866b0bcb4726","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/f3322baa3a8ac87730feae952c1146269d78e098","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"tags":["nvd","cve.org"],"ingestedAt":"2026-09-25T11:06:38.878Z","slug":"CVE-2026-97952","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nsunvdc: unmap LDC cookies when the descriptor send fails\n\n__send_request() maps the request's pages into the LDC channel's map\ntable (ldc_map_sg()), fills in the descriptor and marks it\nVIO_DESC_READY before ringing the doorbell via __vdc_tx_trigger().\nWhen the trigger fails, the error path only prints a message: the\ndescriptor stays READY and the cookies are never unmapped. The\nmapping is normally released in vdc_end_one() when the peer completes\nthe descriptor - but a descriptor whose doorbell was never sent will\nnever complete, and since dr->prod is not advanced on failure, the\nreset path (vdc_requeue_inflight(), which walks [cons, prod)) never\nvisits it either. The map table entries are leaked permanently.\n\nSince commit a11f6ca9aef9 (\"sunvdc: Do not spin in an infinite loop\nwhen vio_ldc_send() returns EAGAIN\") trigger failures occur in\npractice under load, so every resulting I/O error also leaks one\nrequest's worth of entries from the fixed-size (8192 entries per\nchannel) map table. Because the allocator hands out contiguous\nranges, fragmentation makes large multi-segment requests fail first\nas the table drains, until ldc_map_sg() fails permanently and the\ndisk is dead until reboot.\n\nIt also makes any retry-based recovery unusable: requeuing the\nrequest on -EAGAIN remaps the pages on every attempt, overwriting\ndesc->cookies and orphaning the previous mapping, so the table\ndrains at the retry rate. This is the memory exhaustion observed\nwhen the requeue approach was first tested in October 2025.\n\nRoll back on failure: unmap the cookies, mark the descriptor FREE\nagain and clear the request entry. If the trigger failed with\n-ENOTCONN, __vdc_tx_trigger() has already reset the port, which\ntears down and reallocates both the dring and the LDC channel\nincluding its map table - nothing to roll back, and the stale\ndescriptor must not be touched.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}